Basic Properties of Thin-Disk Oscillations

In this paper oscillations on geometrically thin disks are reviewed, focusing on two issues. One is the characteristics of disk oscillations. The other is possible excitation mechanisms of these oscillations. The main purpose of this paper is to clarify the physics and dynamics involved in these issues. We consider both Newtonian and general-relativistic disks, since a comparison of the oscillations on both disks clarifies the differences among these two oscillations and is helpful for understanding the unique properties of relativistic disks. Furthermore, we sometimes refer to stellar oscillations, since a comparison with stellar oscillations is helpful to have a deeper understanding of the disk oscillations, especially of the excitation mechanisms.